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本文综述了半导体氧化物光催化裂解水制氢的反应机理,以及近年来半导体光催化裂解水制氢的研究进展。讨论了各种因素对材料光催化性能的影响以及改性方法,并对今后的研究方向提出了一些建议。 相似文献
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本文综述了半导体氧化物光催化裂解水制氢的反应机理,以及近年来半导体光催化裂解水制氢的研究进展.讨论了各种因素对材料光催化性能的影响以及改性方法,并对今后的研究方向提出了一些建议. 相似文献
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本文综述了半导体氧化物光催化裂解水制氢的反应机理,以及近年来半导体光催化裂解水制氢的研究进展。讨论了各种因素对材料光催化性能的影响以及改性方法,并对今后的研究方向提出了一些建议。 相似文献
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钙钛矿型复合氧化物光催化研究进展 总被引:9,自引:0,他引:9
扼要叙述了钙钛矿型复合氧化物(ABO3)作为光催化剂的研究进展。包括结构,机理,制备,改性和研究现状。强调了结构与性能之间的关系并对其研究方向提出了自己的见解。 相似文献
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系统总结了金属有机框架(MOFs)基材料在光催化还原CO2中的最新研究进展, 其中包括MOFs直接作为光催化剂和作为复合光催化2个主要部分, 讨论了MOFs基光催化剂在催化还原CO2方面展现出的独特优势, 并对MOFs基光催化剂的结构稳定性与CO2转化效率等问题进行讨论与分析, 对未来发展趋势进行了展望. 相似文献
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The acceleration of industrialization and the continuous upgradation of consumption structure has increased the atmospheric content of CO2 far beyond the past levels, leading to a serious global environmental problem. Photocatalytic reduction of CO2 is one of the most promising methods to solve the problem of rising atmospheric CO2 content. The core of this technology is to develop efficient, environment-friendly, and affordable photocatalysts. A photocatalyst is a semiconductor that can absorb photons from sunlight and produce electron-hole pairs to initiate a redox reaction. Owing to their low specific surface areas, significant electron-hole recombination, and less surface-active sites, bulk photocatalysts are not satisfactory. Ultrathin layered materials have shown great potential for photocatalytic CO2 reduction owing to their characteristics of large specific surface area, a large number of low-coordination surface atoms, short transfer distance from the inside to the catalyst surface, along with other advantages. Photoexcited electrons only need to cover a short distance to transfer to the nanowafer surface, and the speed of migrating electrons on the nanowafer surface is much higher than that in the layers or in the bulk catalyst. The ultrathin structure leads to significant coordinative unsaturation and even vacancy defects in the lattice structure of the atoms; while the former can be used as active sites for CO2 adsorption and reaction, the latter can improve the separation of the electron-hole pair. This review summarizes the latest developments in ultrathin layered photocatalysts for CO2 reduction. First, the photocatalytic reduction mechanism of CO2 is introduced briefly, and the factors governing product selectivity are explained. Second, the existing catalysts, such as g-C3N4, black phosphorus (BP), graphene oxide (GO), metal oxide, transition metal dichalcogenides (TMDCs), perovskite, BiOX (X = Cl, Br, I), layered double hydroxide (LDH), 2D-MOF, MXene, and two-dimensional honeycomb-like Ge―Si alloy compounds (gersiloxenes), are classified. In addition, the prevalent preparation methods are summarized, including mechanical stripping, gas stripping, liquid stripping, chemical etching, chemical vapor deposition (CVD), template method, self-assembly of surfactant, and the intermediate precursor method of lamellar Bi-oleate complex. Finally, we introduced the strategy of improving photocatalyst performance on the premise of maintaining its layered structure, including the factors of thickness adjustment, doping, structural defects, composite, etc. The future opportunities and challenges of ultrathin layered photocatalysts for the reduction of carbon dioxide have also been proposed. 相似文献
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In‐depth understanding of the catalytic active sites is of paramount importance for the design of efficient electrocatalysts for CO2 conversion. Here we highlight the structural evolution of SnO2 nanosheets for electrocatalytic CO2 reduction. The transformation of SnO2 into metallic Sn would occur on the surface of catalyst during the catalytic process, followed by enhanced selectivity and activity for the conversion of CO2 to HCOOH. Electrocatalytic characterization and structural analysis demonstrate that the metallic Sn derived from structural evolution plays a dominant role in the CO2 reduction to HCOOH. This work deepens the understanding of the catalytic mechanism and provides a new pathway for the rational design of advanced electrocatalysts for CO2 reduction. 相似文献
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Burning of fossil fuels increases CO2 concentration in the atmosphere, resulting in a series of climate- and environment-related concerns such as global warming, sea-level rise, and melting of glaciers. Therefore, utilization of renewable energy to reduce the CO2 concentration, in order to realize a sustainable development, is urgent. Capturing and utilizing CO2, a greenhouse gas, can not only address these concerns but also alleviate the current scenario of energy shortage. Thermal catalytic CO2 hydrogenation offers various pathways with high conversion efficiencies to produce fuels and industrial chemicals including CO, HCOOH, CH3OH, and CH4. However, CO2 is chemically inert due to the highly stable C=O bond. Thus, harsh reaction conditions such as high temperature and pressure are required for CO2 hydrogenation. 相似文献
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固体氧化物电解池是一种高效、环境友好型的能量转换器件,可以直接将电能转化为化学能. 本文介绍了近年来作者课题组在固体氧化物电解池直接用于CO2还原的研究进展,并以阴极材料为主着重讨论了金属陶瓷电极和混合导电型钙钛矿氧化物电极的研究工作,最后展望了未来固体氧化物电解池直接电解CO2的研究思路和方向. 相似文献
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单原子催化剂在光催化二氧化碳还原中的研究进展 总被引:1,自引:0,他引:1
通过光催化技术将二氧化碳转化成增值的含碳化学品或燃料是解决能源危机和温室效应的一种可持续性方法. 开发高效、 廉价及高稳定性的光催化剂是提高光催化二氧化碳还原(CO2RR)效率所面临的一大挑战. 单原子催化剂由于具有原子利用率高及电子环境可调等特性而在催化领域被广泛研究. 在光催化二氧化碳还原中, 金属单原子的加入不仅可调节光催化剂的能带结构及吸光性能等物理性质, 还可以有效提高其光生电荷转移效率, 并为研究光催化反应机理提供理想的平台. 近年来, 单原子光催化剂在二氧化碳还原领域的研究发展迅速. 本文综合评述了单原子催化剂在光还原二氧化碳反应中的研究进展, 介绍了不同载体的单原子催化剂的典型研究成果, 并展望了未来的研究趋势. 相似文献
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采用柠檬酸络合法制备铋层钙钛矿K0.5La0.5Bi2Ta2O9 (KLBT), 通过酸化处理得到质子化层状钙钛矿H1.9K0.3La0.5Bi0.1Ta2O7(HKLBT)光催化剂, 并通过热重-差热(TG-DSC)、X射线衍射(XRD)、紫外-可见漫反射(DRS)、X射线光电子能谱(XPS)等技术对其进行了表征和分析.考察了前驱体KLBT的不同焙烧温度对HKLBT制氢活性的影响. 结果表明, 柠檬酸络合法能在较低温度下合成高结晶度纯相HKLBT, 前驱体经900℃焙烧制备的HKLBT催化剂活性最高, 在纯水中的产氢速率达236.6μmol·h-1; 长时间活性测试表明HKLBT具有完全分解水同时产氢产氧能力,且具有较好的稳定性. 相似文献
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Solar energy is the largest renewable energy source in the world and the primary energy source of wind energy, tidal energy, biomass energy, and fossil fuel. Photocatalysis technology is a sunlight-driven chemical reaction process on the surface of photocatalysts that can generate H2 from water, decompose organic contaminants, and reduce CO2 into organic fuels. As a metal-free polymeric material, graphite-like carbon nitride (g-C3N4) has attracted significant attention because of its special band structure, easy fabrication, and low costs. However, some bottlenecks still limit its photocatalytic performance. To date, numerous strategies have been employed to optimize the photoelectric properties of g-C3N4, such as element doping, functional group modification, and construction of heterojunctions. Remarkably, these modification strategies are strongly associated with the surface behavior of g-C3N4, which plays a key role in efficient photocatalytic performance. In this review, we endeavor to provide a comprehensive summary of g-C3N4-based photocatalysts prepared through typical surface modification strategies (surface functionalization and construction of heterojunctions) and elaborate their special light-excitation and response mechanism, photo-generated carrier transfer route, and surface catalytic reaction in detail under visible-light irradiation. Moreover, the potential applications of the surface-modified g-C3N4-based photocatalysts for photocatalytic H2 generation and reduction of CO2 into fuels are summarized. Finally, based on the current research, the key challenges that should be further studied and overcome are highlighted. The following are the objectives that future studies need to focus on: (1) Although considerable effort has been made to develop a surface modification strategy for g-C3N4, its photocatalytic efficiency is still too low to meet industrial application standards. The currently obtained solar-to‑hydrogen (STH) conversion efficiency of g-C3N4 for H2 generation is approximately 2%, which is considerably lower than the commercial standards of 10%. Thus, the regulation of the surface/textural properties and electronic band structure of g-C3N4 should be further elucidated to improve its photocatalytic performance. (2) Significant challenges remain in the design and construction of g-C3N4-based S-scheme heterojunction photocatalysts by facile, low-cost, and reliable methods. To overcome the limitations of conventional heterojunctions thoroughly, a promising S-scheme heterojunction photocatalytic system was recently reported. The study further clarifies the charge transfer route and mechanism during the catalytic process. Thus, the rational design and synthesis of g-C3N4-based S-scheme heterojunctions will attract extensive scientific interest in the next few years in this field. (3) First-principle calculation is an effective strategy to study the optical, electrical, magnetic, and other physicochemical properties of surface strategy modified g-C3N4, providing important information to reveal the charge transfer path and intrinsic catalytic mechanism. As a result, density functional theory (DFT) computation will be paid increasing attention and widely applied in surface-modified g-C3N4-based photocatalysts. 相似文献
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E. García-Pérez J. B. Parra C. O. Ania A. García-Sánchez J. M. van Baten R. Krishna D. Dubbeldam S. Calero 《Adsorption》2007,13(5-6):469-476
The adsorption properties of CO2, N2 and CH4 in all-silica zeolites were studied using molecular simulations. Adsorption isotherms for single components in MFI were both
measured and computed showing good agreement. In addition simulations in other all silica structures were performed for a
wide range of pressures and temperatures and for single components as well as binary and ternary mixtures with varying bulk
compositions. The adsorption selectivity was analyzed for mixtures with bulk composition of 50:50 CO2/CH4, 50:50 CO2/N2, 10:90 CO2/N2 and 5:90:5 CO2/N2/CH4 in MFI, MOR, ISV, ITE, CHA and DDR showing high selectivity of adsorption of CO2 over N2 and CH4 that varies with the type of crystal and with the mixture bulk composition. 相似文献